Chttck



J.- c. DUFRESNE.

CHUCK.

APPLICATION HLED NOV. 2.1917.

Patented June 3, 1919.

2 SHEETS-SHEET 1 0676 ajfi'eaize I /lttowe4 J. C..DUFRESNE.

CHUCK. APPLlCATION FILED NOV. 2. 1 11.

Patented Jun 3, 1919.

2 SHEETS-SHEET 2.

JERE o. DUFRESNE, or RAHWAY, NEW JERSEY.

CHUCK.

Specification of Letters Patent.

Patented June 3, 1919.

Application filed November 2, 1917. Serial No. 199,935.

To all whom it may concern:

Be it known that I, JERE C. 'DUFRESNE, a citizen of the United States, residing at Rahway, in the countyof Union and State of New Jersey, have invented new and useful Improvements in Chucks, of which the following is a specification.

The present invention has reference to chucks, and more particularly to the type of chuck in which a safety connection is employed between the tool and the chuck body, this connection being designed to yield in one way or another when subjected to a predetermined force, with the result that the tool is uncoupled from its driving mecha-' nism, and neither the one nor the other is injured thereby.

The invention is 'primarlly a development of that disclosed in my prior application, i

Serial No. 132,636, filed November 21, 19-16; and it proposes certain improvements, hereinafter fully described, in or relating to the construction of the chuck \body andthe collet, the mounting of the collet, and the various retaining devices provided for normally holding the tool and the safety connection in place. J

Other improvements and advantages embodied in the invention will appear as the description proceeds.

The accompanying drawing illustrates one form which the invention may take in actual practice, and therein:

Figure 1 is a view of the complete'implement, partly in longitudinal seotion'and partly in side elevation.

Fig. 2 is a fragmental longitudinal section of the chuck body. i

Figs. 3 and 4 are transverse sections taken on the lines 33 and M, respectively, of Figs. '1 and 2.

Figs. 5 and 6 are, respectively, aside elevation and an end View of the collet.

Figs. 7', 8 and 9 are detail views, respec-' tively, of the safety connection, its retaining device, and the'tool ejector.

As shown in said drawing, the chuck consists, asa whole, of'the following'main parts or elements,to-wit; the chuck'body 1, the

The collet 2 receives therein the shank of the drill or other cutting tool 6, and is formed for that purpose with a specially constructed bore, the outer or front portion 7 of which is slightly tapered and conforms to the cross-sectional shape of the tool shank, as will'be understood. The cylindrical inner or rear portion 8 of the bore opens through the rear end of the collet and serves as a socket-for the reception of a tool ejector 9, which has the form of a block or plug,

provided upon its front face with a central rib or shoulder 10, the latter projecting into contact,-or substantially so, with the tang j 11 of thetool, which extends through a tang slot l2- in the partition 13 that separates the two portions 7 and 8 of the bore.

The collet is designed to fit. within the socket 1, and is held in place therein by the sliding collar 3 in substantially the same way asin the earlier construction; that is to say,-through the intermediary of a plurality of hardened steel coupling pins 14., loosely mounted in radial openings 15 pierced through the wall of the socket, the headed outer ends of the pins engaging the inclined inner wall 16 of the collar. Instead of the outer surface of the collet being formed with an annular V-shaped groove, as in the aforesaid earlier construction, it is cutaway or'reduced in thickness intermediate its ends, thus forming a neck 17, which connects the front and rear portions of the collet, the rear portion-18 of the circumferential wall of the neck being made sloping so as to exert the desired cam action upon the pins. Otherwise,the two constructions are similar, so far as this feature is concerned, and the operation is the same, or

hence, to the cutting tool, is effected by the safety deviceabove referred to, which device,like the one in my earlier construction, comprises a member adapted to be sheared or broken when subjected to an excessive strain. In the present construction, I prefer to' use a single long pin '1'9, in place of the series of'short pins employed in the earlier construction, and this pin I insert through a pair of diametrically-opposite V openings 20, formed through the rear portion'of the collet. The ends of the pin project beyond the collet, and are received in slots 21- and 22, formed in inner wall of the socket, the outer portions of these slots being flared at one side, as indicated at 23 and 24, so that their inclined walls serve as ing a width which approximately equals the diameter of the adjacent pin end, while the width of the slot 22 is considerably greater than the diameter of the other pin end, so that the latter end is afforded considerable lateral play therein. The aforesaid straight portions register directly with a pair of openings 25 and 26, so that the pin, if wedged or broken, may readily be driven out of the chuck by means of a suitable instrument. There are preferably three pairs of openings 20, as shown in Fig. 6, the openings being arranged equidistantly and having different diameters, so as to accommodate shearing pins of different sizes, and any one of these pairs can be brought into register with the slots. It follows, therefore, from the foregoing, that the shearing pin willbreak or shear off at one end only, i. 6., the end which is received in the narrow slot 21, when the torsional strain exerted upon the tool reaches a predetermined point, but will-snap or shear off at both ends when the tool is subjected to an excessively high pushing action, as will be understood. 1

The bore of the socket 4 is likewise made in two diameters, partly to facilitate the removal of the collet, and partly to permit the formation of the pin-receiving slots 21 and- 22 and their flaring mouths 28 and 24, the rear or inner end of the bore being sli htly widened, as indicated at 27, (Fig. 2 in order to enable the collet to be turned, after the pin has sheared, until the ends of said pin are brought into line with a pair of Ion-- gitudinal grooves 28. Consequently, the removal of the collet from the socket after shearing is insured even though a bur is formed on the pin as a result of the shear-- ing, one of these openings being provided for each pair of openings 20 so that the position of the plunger may be adjusted in accordance with whichever pair of pin openings is in use. The plunger is provided intermediate its ends with an upwardlytapered neck 32, which engages in a circum-- ferential groove. 33 formed in the shearing pin, each plunger opening intersecting the adjacent pin opening 20 in order to permit such engagement; The outward pressure of the spring 30 will, in consequence, cause the plunger to frictionally bind against the 9, is bifurcated or slotted at its rear por-' tion, as indicated at 34,- the slot passing through the axis of the ejector-and being wide enough to enablethe shearing pin to also pass thercthrough; and it is this pin and slot connectio-n,:so speek,'which holds the ejector in place and prevents rotation thereof. It will be seenthat the ejector extends through the open inner or rear end of the collet, as shown by Fig. 1; and by reason ofthis projection of the ejector the removal of the tool from the collet can be readily effected by first withdrawing the collet from the socket or chuck body and loosening the screw 35 sufiieiently to disengage it from the tool shank, and finally striking the projectingend of the ejector a sharp blo-w with any suitable means, when the rib or shoul-- der '10 of thefejector normally engaging the tangof the toolwill drive'the said-tool outwardly from the bore of the collet. rear endwall'27 of the bore of the socket 4 including the rear diametrically enlarged or widened portion 27 thereof has a reduced centrally located boreextension 27", as shown by Figs. 1 and 2, and when the collet 2 is held in rotatable connection with the socket t'by the pin 19, the rear end of said collet and the rear'pro-jecting slotted portion 3a of the ejector 9 are positioned in advance ofthe rear end Wall of the socket, the bore extension 27 serving as a receptive means for the portion of the ejector projecting rearwardly from the rear end of the collet. Essentially,therefore,- there must be a space between the rear ends of the collet and ej ector and the rear end wall of the socket bore to effect a complete rotative release of the collet from the socket when the pin is sheared, for reasons as follows: When the pin 19 is sheared the collet 2 with the drill 6 stops rotating and-the advance movement or feed thereof ceases, but the socket or chuckbody 4: continues to rotate and advances over the collet toward the work until the operator disengages the feeding mecha nism. The space between the rear ends of the collet and ejector and the end wall 27 of thebore 27 give a sufficient lapse of time" as the socket moves forwardly over the col-- let before the said rear ends of the collet and ejector contact with the rear end Wall The sufficient to shear the pin 19 will cause the pins 14 to lip over the declining surface of said neckand cease to perform any binding function relatively between the collar or sleeve 3 and the collet, and hence the collet will not rotate and breakage of the drill is avoided. Subsequent to the shearing of one pin another may be inserted to again connect the collet and socket for united rota-.

tion and thereby set the several parts in normal working position.

The tool 6 is kept from falling out of the collet by means of a hollow screw 35, which fits in an opening 36 formed through the forward portion of the collet, the lower end of the screw contacting with a flattened portion or seat 37 with which the tool is provided. 5 I i I claim as my invention 1. In a chuck, the combination of a socket having a seat in its inner wall; a collet removably fitted in said socket and having a bore to receive the tool shank and also having an opening in register with said seat; and a shearing member mounted in the collet and projecting at one end through said opening into said seat, to transmit the nor- 7 mal rotary movement of the socket to the collet, but adapted to break when subjected to excessive pressure so as to imcouple the collet from the socket; said seat having a flared inlet for directing said shearing membar end thereinto during the insertion of the collet in said socket. r e

2. In a chuck, the combination of a socket having a longitudinal seat in its inner wall; a collet removably fitted in said socket and having a bore to receive the tool shank and also having an opening in register with the rear end of said seat; and a shearing pin mounted in said collet and projecting at one end through said opening into said seat, to transmit the normal rotary movement of the socket to the collect, but adaptedto break when subjected to excessive pressure so as to uncouple the collet from the socket; said seat having an inclined guide'wall leading to its inlet end to direct said pin end thereinto during the insertion of the collet in the socket.

3. In a chuck, the combination of a socket having its inner wall formed with a pair of' oppositely-located seats; a collet removably fitted in said socket and having a bore to receive the tool shank and also having a pair of alining, transverse openings in register 'with said seats; and -a member inserted through said openingsv and having its ends projecting into said seats, to transmit the a normal rotary movement of the socket to the collet, but adapted to shear oil at either end when subjected to excessive pressure, so

as to uncouple the collet from the socket;

said seats having guides leading to their inlet ends for directing the ends of said shearing member thereinto during the insertion of the collet. v a

4. In a chuck, the combination ofa socket having its inner wall formed with a pair of oppositely-located, longitudinal seats; a collet removably fitted in said socket and having a bore to receive the tool shank and also having arpair of allning, transverse openings in register with the rear ends of said seats; and a pin inserted through said openings and projecting at its ends into said seats, to transmit the normal rotary move- 7 ment of the socket to the collet, but adapted to shear ofi at either end when subjectedto excessive pressure so as to uncouple the col let from the socket; each seat having an 1n-Y:

clinedguide Wall leading to its inlet end to direct the adj acent'pin end thereinto during the insertion of the collet. I

5. In a chuck, the combination of a socket having its inner wall formed with a pair of oppositely-located seats; a collet removably fitted in said socket and having a bore to re ceive the tool shank and also having a pair of alining, transverse openings in register with said seats; and a member inserted through said openings and having its ends projecting into said seats, to transmit the normal rotary movement of the socket to the collet, but adapted to shear off when subj ected to excessive pressure so as to uncouple the collet from the socket; one seat and the adjacent opening having a greater width than the other seat and opening, so that said member will shear ofi' atone end only when sufiicient torsion is exerted on the collet, and at both ends when suflicient pressure is im-' posed longitudinally on the collet.

6. In a chuck, the combination of a socket having its inner wall formed with a pair of oppositely-located seats; a-collet removably fitted in said socket and having a bore to re ceive the tool shank and also having a pair of alining, transverse openings in register with said seats; and a member inserted through said openings and having its ends projecting into said seats, to transmit the normal rotary movement of'the socket tothe collet, but" adapted to shear off when subjected to excessive pressure so as to uncouple the collet from the socket; one seat and the adjacent opening having a greater width than the other seat and opening, so that said member will shear off at one end only when suflicient torsion is exerted on the collet, and at both ends when sufficient pressure is'imbetween the inner end of the collet and the v end walls of the bore of the socket, a-notched safety connection between said socket and collet for transmitting the normal rotary movement of the former to the latter, but adapted to shear off when subjected to excessive pressure so as to uncouple the collet from the socket and permit the latter to have endwise shifting movement on thecollet:;.

anda spring-controlled detent engaging in the, notch in said connection to hold the same against displacement.

8. In a chuck, the combination ofa socket having a bore; a collet removablyfittediin the socket and having a bore to receive the tool shank, aspace being normally provided.

between the inner end of the collet and the end walls of the vbore ofthe socket; a single,

soft metal pin connecting said socket and collet togetherto transmit the normal rotary movement of the former to the'latter, but adapted to shear ofi' when subjected'to excessive pressure so as to uncouple the collet.

from the socket and permit the latter to have endwise shifting movement on'the col let; and a yielding retaining member en gaging said pin to hold it against-lendwise movement;

9. In a chuck, the combination of a socket having a bore; a collet removably fitted therein and having a bore to receive the tool shank, a space being normally provided between the inner end of the collet and the end walls of the boreof the socket; a notched pin connecting said socket and collet together to transmit the normal rotary. movement of the former to the latter, but adapted to shear 011' when subjected to excessive pressureso as to uncouple the collet vfrom the socket and permit the latter to have endwise shifting movement on the collet; and a retaining member engaging in the notch in said pin to hold the pin against endwise movement.

10. In a chuck, the combination of; a socket; a collet removably fitted therein and having a bore to receive the tool shank; said socket and collet having alining, transverse openings, and the collet also having an 0 ening in one end which intersects the rstnamed opening in said collet; a connecting pin inserted through the alining openings in the socket and collet for transmitting the normal rotary movement of the former to the latter but adapted to shear off when subjectedto excessive pressure so as to uncouple the collet: from thesocket; and a member. mounted in'the second-named opening in said collet'for engagement-With said pin, to

hold it against endwise :movement.

11. In a chuck, .the combination of a socket; a. collet removably fitted therein and having a bore to receive the tool shank; said socketiandcollet having alining, transverse openings, and the collet also having an opening in one end which intersects the firstnamed opening in said-collet; a connecting pin inserted through the alining openings in the socket and collet for transmitting the normal rotary movementi of the former to the latter, butadapted to shear off when sub-' jected to excessive pressure'so as to uncouple the colletsfrom the socket, said pin having a notch therein; and" aspring-controlled detent mounted-in the second-named opening in said collet for engagement in said notch to hold the pin against endwise movement.

12. In 1 a chuck, the combination of a socket; acollet removably fitted therein and having a bore to receive the tool shank, said socket and collet beingformed with alining, transverse openings;. a connecting pin inserted through said openings for transmitting the normal rotary movement of the socketto the collet; but adapted to shear off whensubjected to excessive pressure so as to uncouple the collet, from thesocket; and a tool ejector fitted in the bore ofsaid collet and engagedby said pin, whereby it is held in place.

13. In a chuck, thecombination of a socket; acolletremovably fitted therein and having a bore to receive the tool shank, said socket and collet being formed with, alining, transverse openings; a connection: pin inserted through said openings for transmitting thenormal rotary movement ofthesocket to the collet, but'ada-pted to shear ofi? when subjected-toexcessivepressure so as touncouple; the collet: from the socket; and atool ejector fittedin the bore ofsaidcolletand formed with a bifurcated portion which: straddles, said pin, whereby saidejector; is held in place; i

14. In a chuck, the: combination of :a socket-;- acollet, removably, fitted therein and havinga bore to receivethe tool shank, said socket and collet being formed" with alining, transverse openings, and the collet also being formed-with a secondctra-nsverse opening leading into-its bore; a connecting pin'inserted through thefirst-named transverse openings for transmitting the normal rotary, movement of the socket to the collet, but adapted to shear off when subjected to excessive-pressure so-as to-uncouple the collet from the socket; and a member fitting inthe second-named transverse; opening in said collet for engagement with the tool shank, ,to retain'the tool in place;v

15. Ina. chuck, the combination of a socket having a bore with the rear portion of greater diameter than the forward portion thereof, a collet removably fitted in the bore of the socket and of itself having a bore to receive the tool shank and also provided with a transverse opening through its forward portion, a shearable connection pin inserted through the socket and collet, and means fitted in said transverse opening of the collet and engaging the tool shank to hold the tool in place.

16. In a chuck, the combination of a socket having a bore with the rear portion slightly greater in diameter than the forward portion thereof, a collet reinovably fitted in said socket and of itself having a bore to receive a tool shank, and a connection pin inserted transversely through the socket and collet and adapted to shear ofi when subjected to excessive pressure to un couple the, collet from the socket, the socket when liberated having an endwise advance movement on the collet to liberate the latter.

17. In a chuck, the combination of a socket having a longitudinal bore and transverse openings therethrough, a collet removably fitted in the bore of the socket and of itself having a bore to receive a tool shank, a space being normally provided between the inner end of the collet and the terminal wall of the socket bore, and a shearable connection pin inserted through the socket and collet, the shearing of the said pin permitting the socket to advance endwise over the collet toward the work and causing the said collet and the tool carried thereby to cease rotation, the said space providing for a sufiicient time lapse prior to the engagement of the inner end of the collet with the terminal wall of the socket bore sufiicient to check the operating mechanism of the socket and thereby preventing rotative actuation of the collet and injury to the tool carried by the collet.

18. In a chuck, the combination of a socket, a collet removably fitted in the socket and provided with a bore to receive a tool, and a shearable connecting pin inserted through the socket and collet, the socket be ing automatically shiftable endwise over the collet and rotatively disconnecting the-latter and the tool thereof after the connecting pin has been sheared and prior to stoppage of the operation of said socket.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JERE C. DUFRESNE.

Witnesses:

EDWARD J. EIGHER, JOSEPH H. BowDEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. G. 

